Sulfur Burps on Ozempic, Mounjaro & Zepbound: Causes and What Stops Them

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Updated September 15, 2026 · By the GLP-1 SOS™ editorial team

"Sulfur burps" (rotten-egg burps) are one of the most searched, least explained side effects of Ozempic®, Wegovy®, Mounjaro® and Zepbound®. They are not listed on the medication label by that name, but thousands of GLP-1 users describe the same thing: a foul, eggy burp that shows up hours after eating, often with bloating, and sometimes with diarrhea or constipation. Here is what causes them, what stops them and what does not.

Short answer: the smell is hydrogen sulfide, produced when protein sits in a slowed stomach and gut long enough for bacteria to ferment it. GLP-1s slow gastric emptying, so meals ferment instead of moving. What helps: smaller meals with less sulfur-heavy protein at once, ginger to keep the stomach moving, digestive enzymes so protein is broken down before bacteria get it, and a probiotic to rebalance the gut. Antacids and mints do not touch the cause.

What sulfur burps are

A normal burp is swallowed air and carbon dioxide. A sulfur burp carries hydrogen sulfide (H2S), the gas that smells like rotten eggs. Hydrogen sulfide is made by gut bacteria when they break down sulfur-containing amino acids (cysteine and methionine, abundant in eggs, meat, dairy, cruciferous vegetables, garlic and onions) and certain sulfate-containing foods and drinks.

Why they happen on a GLP-1

  1. Slowed gastric emptying. Semaglutide and tirzepatide keep food in the stomach for hours longer than normal. Protein that would have been digested and absorbed sits, warms and ferments. That fermentation is the source of the gas.
  2. Less stomach acid contact and slower enzyme action. Digestion is a timed process; when the timing stretches, bacteria get access to protein that enzymes have not finished breaking down.
  3. A changed microbiome. Eating less, eating less variety and, for many people, more protein per meal shifts the gut toward sulfur-reducing bacteria.
  4. Constipation. Waste that sits in the colon ferments too. Sulfur burps and GLP-1 constipation are usually the same problem at two ends of the gut.

They tend to be worst in the day or two after an injection, when gastric emptying is slowest, and after large, protein-heavy meals.

What stops sulfur burps

1. Smaller meals, protein spread out

The single biggest lever. Three or four small meals with 20 to 30 g of protein each ferment far less than one large dinner with 60 g. Eat slowly, stop at "not hungry," not "full."

2. Ginger to keep the stomach moving

Standardized ginger extract (5% gingerols) has been shown to speed gastric emptying in controlled studies (Wu et al., 2008; Hu et al., 2011). Less time in the stomach means less fermentation. It also settles the nausea that often arrives with the burps.

3. Digestive enzymes with the meal

Proteases and lipases break protein and fat down before bacteria can ferment them. Taken with dinner, the meal most likely to sit overnight, they cut off the gas at its source.

4. A multi-strain probiotic, daily

Rebalancing the gut away from sulfur-producing species takes daily use for two to four weeks; it is a slow lever, but it is the one that makes the difference last.

5. Peppermint for the bloat that comes with it

Peppermint relaxes the gut wall and reduces the trapped-gas pressure; it is the best-studied herb for functional bloating (Alammar et al., 2019).

6. Fix the constipation

If you are also backed up, nothing above will fully work until waste is moving. Magnesium (250 mg citrate/oxide with dinner) and water handle that. See the GLP-1 constipation guide.

All six are the design of GLP-1 SOS Daily Gut Relief: 200 mg ginger at 5% gingerols, digestive enzymes, a 19-strain probiotic, 50 mg peppermint and 250 mg magnesium, two capsules with dinner.

What does not work

  • Antacids and Pepto-Bismol®. They neutralize acid or coat the stomach; the gas is made downstream by bacteria. Bismuth can mask the smell temporarily and turns the stool black.
  • Mints and gum. Cover the smell for minutes and add swallowed air.
  • Cutting all protein. You need protein on a GLP-1 to keep muscle. Spread it out instead of removing it.
  • Skipping meals to avoid burps. An empty stomach still ferments what is left, and skipping makes the next meal bigger.

Foods that make sulfur burps worse

Eggs, red meat, dairy, whey protein shakes, broccoli, cabbage, Brussels sprouts, garlic, onions, beer and wine, dried fruit and sulfite-preserved foods. You do not have to avoid them; you have to eat them in smaller amounts and not all in one sitting.

When to call your prescriber

Sulfur burps alone are a nuisance, not a danger. Call your doctor if they come with persistent vomiting, severe or worsening abdominal pain, fever, blood in the stool, or if you cannot keep fluids down. Those can signal something other than fermentation.

Frequently asked

Do sulfur burps mean the GLP-1 is working?

They mean the medication is slowing your stomach, which is part of how it works, but the burps themselves are a fermentation side effect, not a sign of weight loss.

How long do sulfur burps last on Ozempic or Mounjaro?

Most people notice them during dose increases and in the two days after an injection. For some they fade after the first months; for others they continue as long as gastric emptying is slowed, which is why a daily routine matters.

Does Pepto-Bismol stop sulfur burps?

It can reduce the smell for a while because bismuth binds hydrogen sulfide, but it does nothing about the fermentation and is not meant for daily use. It also turns the tongue and stool black.

Stop the egg burps — Daily Gut Relief, 60-day money-back guarantee

References

  • Wu KL, et al. Effects of ginger on gastric emptying and motility in healthy humans. Eur J Gastroenterol Hepatol. 2008;20(5):436-440.
  • Hu ML, et al. Effect of ginger on gastric motility and symptoms of functional dyspepsia. World J Gastroenterol. 2011;17(1):105-110.
  • Alammar N, et al. The impact of peppermint oil on the irritable bowel syndrome: a meta-analysis of the pooled clinical data. BMC Complement Altern Med. 2019;19:21.
  • Wilding JPH, et al. Once-weekly semaglutide in adults with overweight or obesity (STEP 1). N Engl J Med. 2021;384:989-1002.

Related guides: GLP-1 constipation · Shot-day nausea · Ingredients · FAQ

This article is educational and is not medical advice. Ozempic® and Wegovy® are trademarks of Novo Nordisk A/S; Mounjaro® and Zepbound® are trademarks of Eli Lilly and Company; Pepto-Bismol® is a trademark of Procter & Gamble. GLP-1 SOS™ is not affiliated with any of them. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.